The present application claims priority upon Japanese Patent Application No. 2001-310435 filed on Oct. 5, 2001 which is herein incorporated by reference.
1. Field of the Invention
The present invention relates to an air cleaner comprising an evaporated fuel process device (hereinafter, referred to as xe2x80x9ccanisterxe2x80x9d) for adsorption process of evaporated fuel which remains near an injector or a carburetor of a vehicle and includes a large amount of hydrocarbon (HC) to be one of the cause of air pollution, and for prevention of evaporated fuel from being released in the atmosphere.
2. Description of the Related Art
Conventionally, this type of air cleaner 1, for example as shown in FIG. 9, comprises a filter element 7 within a filter body 6 comprising a cover 5 and a body 4 having an inlet pipe 2 and an outlet pipe 3, and comprises a cylindrical canister 11 which takes the vertical axis as its center and stores at a discharge side (inner side) of the filter element 7 an adsorbent 10 in between lattice holding members 8, 9 which are arranged concentrically with a predetermined space.
In the air cleaner 1, by air passing through the filter element 7 and the canister 11 in a radial direction, evaporated fuel which remains near the injector or the carburetor is adsorbed by the adsorbent 10 of the canister 11, and evaporated fuel adsorbed by the adsorbent 10 is desorbed by a negative pressure of a suction pipe and processed to be sucked from the outlet pipe 3 to an engine. Thus, evaporated fuel is stopped from being released in the atmosphere and air pollution is prevented.
However, in actuality there was a technical problem as described below.
Namely, with the air cleaner 1 comprising the above described conventional canister 11, since the canister 11 sandwiches the holding member 9 and adheres to the filter element 7, there was fear that evaporated fuel adsorbed by the adsorbent of the canister 11 is taken along and released in the atmosphere from the outlet pipe 3, at the time air from the inlet pipe 2 which has passed the filter element 7 passes the canister 11.
Further, with the conventional air cleaner 1, the adsorbent of the canister 11 is cylindrically arranged taking the vertical axis as the center, so that if a vibration of a vehicle when running is passed on to the air cleaner 1, there is fear that the adsorbent within the canister 11 will move to a lower portion side. As a result, there is formed a space in an upper portion where there is no adsorbent. Further, since the canister 11 sandwiches the holding member 9 and adheres to an entire inner surface of the filter element 7, there is a problem that a resistance of air in the upper portion is small, whereas a resistance of air in the lower portion is large, and blocking at an early stage is brought about in the upper portion of the filter element 7 and life is shortened.
Meanwhile, the present inventors found that evaporated fuel is heavier than the atmosphere, and flows along the bottom in the filter body 6.
This invention is made to solve the above problems, and based on the above finding, an object thereof is to provide an air cleaner comprising a canister where air does not take along evaporated fuel adsorbed by an adsorbent of the canister, and which may lengthen life of a filter element.
In order to achieve the above objects, one aspect of the present invention is an air cleaner comprising a filter element, and a casing having an inlet provided at a primary side of the filter element and an outlet provided at a secondary side, characterized in that an adsorbent adsorbing evaporated fuel is arranged at a bottom of the casing at the secondary side of the filter element.
Further, another aspect of the present invention is an air cleaner comprising a filter element, and a casing having an inlet provided at a primary side of the filter element and an outlet provided at a secondary side, characterized in that an absorbent material adsorbing evaporated fuel is arranged at a bottom of the outlet.
In this invention, it is preferable that the filter element is vertically arranged, and the outlet projects horizontally from a side portion of the casing.
Further, another aspect of the present invention is characterized by comprising a casing storing an adsorbent, for adsorbing evaporated fuel, with a predetermined height horizontally in between a secondary side of a filter element and an outlet.
In this invention, it is preferable that the adsorbent is held by lattice upper and lower holding members. Further, it is preferable that the filter element is horizontally arranged, the outlet vertically projects from a bottom of the casing, there is provided a vertical connecting portion connected to the outlet, and the adsorbent is arranged over the entire horizontal cross section of the connecting portion.